CN105024602A - Stator double-winding asynchronous motor power generation system and control method - Google Patents

Abstract

The invention discloses a stator double-winding asynchronous motor power generation system and a control method, and belongs to the technical field of a frequency conversion AC power generation system. The novel topology uses a filtering inductor, an excitation capacitor and a motor stator winding leakage inductor to form an LCL type filter, and the volume and the weight of the power generation system are reduced. A vector control method based on a dynamic model is used in control, and dynamic and static performance of the system are improved. The frequency conversion AC power generation system comprises a stator double-winding asynchronous motor, a power converter, the LCL type filter, a DC filtering capacitor, a storage battery, a diode, a DC voltage sensor, an AC voltage sensor, an AC current sensor, a controller and a drive circuit; and the system can be used in independent power supply application occasions such as an airplane and a ship.

Description

A kind of asynchronous motor power generation system of stator duplex winding and control method

Technical field

The present invention relates to a kind of stator double-winding asynchronous variable-frequency alternating current power generation system and control method, belong to the technical field of variable-frequency alternating current power generation system.

Background technology

Variable frequency AC power system is the important direction of of how electricity/electric aircraft power source development.Such as large-scale seating plane B787 and A380 all adopts variable frequency AC power system.Along with the continuous increase of airborne power consumption equipment and precision instrument, to the capacity of power-supply system and performance requirement also more and more higher.

Stator double-winding asynchronous (DWIG) is the novel squirrel cage induction motor of one proposed the beginning of this century, and it inherits, and common cage type asynchronous machine structure is simple, cost is low, high reliability.The stator of this generator has double winding, is controlled winding and power winding respectively.Controlled winding is connected to power inverter and regulates the magnetic field of motor and torque, and power winding is to load supplying.They are by means of only magnetic Field Coupling, without electrical connection, and operational excellence under speed change environment, and controller capacity is less, is adapted at applying in high performance independent electric power supply.

The waveform quality of alternating current power-generating system is the important indicator weighing its performance, and relevant criterion has all made detailed regulation to this.In order to meet standard, in the prior art scheme, the controlled winding side of asynchronous motor power generation system of stator duplex winding relies on single inductance (single L) to carry out filtering substantially, and now system often needs larger filter inductance, and this adds the volume weight of system undoubtedly.Controlled winding side in existing design increases exciting capacity, forms the LCL type filter with better filtering characteristic, can effectively filtering high order harmonic component, reduces loss, reduction system bulk weight.

The runnability of asynchronous motor power generation system of stator duplex winding also depends on adopted control strategy simultaneously.Good control strategy not only can eliminate systematic steady state error, improves system dynamic responding speed, can also improve waveform quality and reduce system loss.From existing data, the voltage adjusting method of asynchronous motor power generation system of stator duplex winding mainly controls based on the scalar of steady-state model, does not carry out Controller gain variations based on system dynamic model.The scalar of asynchronous machine controls the dynamic model owing to not considering electricity generation system, so its dynamic and static state performance is undesirable, regulator parameter chooses difficulty.

Summary of the invention

Goal of the invention: for above-mentioned prior art, proposes a kind of asynchronous motor power generation system of stator duplex winding and control method, the high order harmonic component that effective filtering converter produces, and reduces loss.

Technical scheme: a kind of variable-frequency alternating current power generation system, comprise the main power circuit be made up of dual stator-winding induction generator, power inverter, filter inductance, exciting capacity, DC filter capacitor, the accessory power supply be made up of storage battery and diode, the testing circuit be made up of direct current voltage sensor, AC voltage sensor, the first AC current sensor, the second AC current sensor, the control circuit be made up of controller and drive circuit; Wherein:

In described main power circuit, the controlled winding of connecting stator double-winding AC-DC generator after the AC series filtering inductance of described power inverter, described exciting capacity and filter inductance and motor stator winding leakage inductance form LCL type filter; Described LCL type filter is used for while filtering, utilize exciting capacity to provide idle excitation to dual stator-winding induction generator; Described low pressure small-power accessory power supply is used for providing initial excitation for motor; Described testing circuit for detecting DC voltage, AC voltage, the ac-side current in described main power circuit, and transfers to described controller by detecting the detected value obtained; Described controller adopts vector control strategy driving power converter to control.The vector control method based on dynamic model is used on controlling, be easy to project navigator adjuster and parameter thereof like this, and the design of this controller inhibits the interference of load and rotating speed from principle, system therefore can be made under different loads and speed conditions all to have excellent dynamic and static state performance.

A vector control method for variable-frequency alternating current power generation system, comprises the steps:

Step 1, according to AC voltage sensor measured value calculate dual stator-winding induction generator power winding side export alternating voltage effective value u _p, utilize formula (1) to calculate stator flux of motor set-point

${\mathrm{\ψ}}_{\mathrm{\δ}}^{*}=(K_1+K_2\·\frac{1}{p})(u_p^{*}-u_p)+{\mathrm{\ψ}}_0---\left(1\right)$

Wherein: represent the given effective value of power winding output AC voltage, ψ ₀expression system is in stator flux of motor estimated value during quiescent point; K ₁for the proportionality coefficient of proportional and integral controller, K ₂for integral coefficient; P is differential operator;

Step 2, utilizes stator flux observer to set up with the synchronous rotating frame of stator magnetic linkage vector oriented, observation stator magnetic linkage amplitude ψ _δ, and carry out closed loop feedback adjustment, obtain the d shaft current set-point of controlled winding under synchronous coordinate system shown in (2):

$i_{sd}^{*}=(K_3+K_4\·\frac{1}{p})({\mathrm{\ψ}}_{\mathrm{\δ}}^{*}-{\mathrm{\ψ}}_{\mathrm{\δ}})---\left(2\right)$

Wherein: K ₃for the proportionality coefficient of stator magnetic linkage proportional and integral controller, K ₄for the integral coefficient of stator magnetic linkage proportional and integral controller;

Step 3, according to direct current voltage sensor measured value u _cDCwith direct voltage set-point carry out closed loop feedback adjustment, obtain the q shaft current set-point of controlled winding under synchronous coordinate system shown in (3):

$i_{sq}^{*}=(K_5+K_6\·\frac{1}{p})(u_{cDC}^{*}-u_{cDC})$

Wherein: K ₅for the proportionality coefficient of direct-current voltage proportion integral controller, K ₆for the integral coefficient of direct-current voltage proportion integral controller;

Step 4, utilizes the first AC current sensor Survey control winding current values, obtains the d of controlled winding under synchronous coordinate system, q shaft current i after coordinate transform _sdand i _sq, according to the d of controlled winding under synchronous coordinate system that step 2 and 3 obtain, q shaft current set-point with to the d of controlled winding at synchronous coordinate system, q shaft current carries out closed loop feedback adjustment, and obtain the d of controlled winding under synchronous coordinate system, q shaft voltage is given shown in (4):

$u_{sd}^{*}=(K_7+K_8\·\frac{1}{p})(i_{sd}^{*}-i_{sd}-i_{pd})---\left(4\right)$

$u_{sq}^{*}=(K_7+K_8\·\frac{1}{p})(i_{sq}^{*}-i_{sq})$

Wherein: K ₇for the proportionality coefficient of current closed-loop proportional and integral controller, K ₈for the integral coefficient of current closed-loop proportional and integral controller, i _pdbe that the second AC current sensor is measured and the power winding d shaft current value calculated;

Step 5, according to the d of controlled winding under synchronous coordinate system that step 4 is obtained, q shaft voltage is given with the magnetic linkage angle that stator flux observer is measured adopt Sine Wave Pulse Width Modulation or space vector pulse width modulation, the switching tube of driving power converter, controls amplitude and the rotating speed of stator double-winding asynchronous stator rotating magnetic field, thus the work of control system normal table.

Beneficial effect: compared to traditional asynchronous motor power generation system of stator duplex winding, in topological structure of the present invention, main power circuit defines LCL type filter construction, this LCL type filter by filter inductance, exciting capacity and stator double-winding asynchronous in controlled winding stator leakage inductance form, use an inductance lesser than common LCL filter, and electric capacity is except filter action, also play effect double-winding AC-DC generator being carried out to excitation.LCL type filter is compared to common single L filter, owing to having the low-frequency filter characteristics on three rank, thus for same harmonic standard and lower switching frequency, can adopt the design of relatively little filter inductance, the volume weight of effective reduction system also reduces loss.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of variable-frequency alternating current power generation system;

Fig. 2 is the main power schematic equivalent circuit of variable-frequency alternating current power generation system;

Fig. 3 is variable-frequency alternating current power generation system vector control method schematic diagram;

Number in the figure illustrates: in Fig. 1,1, dual stator-winding induction generator; 2, filter inductance; 3, power inverter; 4, exciting capacity; 5, storage battery; 6, diode; 7, filter capacitor; 8, direct current voltage sensor, 9, AC voltage sensor; 10, the first AC current sensor; 11, the second AC current sensor; 12, controller; 13, drive circuit; 14, load.In Fig. 2,15, power inverter equivalent voltage source; 16, LCL type filter, by filter inductance, exciting capacity, motor winding leakage inductance forms; 17, stator double-winding motor stator power winding equivalent electric circuit; 18, stator double-winding motor equivalence magnetizing inductance; 19, stator double-winding motor rotor equivalent circuit; 20, stator double-winding motor stator controlled winding equivalent resistance.

Embodiment

Below in conjunction with accompanying drawing the present invention done and further explain.

Variable-frequency alternating current power generation system as shown in Figure 1, comprises dual stator-winding induction generator 1, three filter inductances 2, power inverter 3, three exciting capacities 4, storage battery 5, diode 6, DC filter capacitor 7, direct current voltage sensor 8, AC voltage sensor 9, first AC current sensor 10, second AC current sensor 11, controller 12, drive circuit 13.Dual stator-winding induction generator 1, three filter inductances 2, power inverter 3, three exciting capacities 4, DC filter capacitors 7 form main power circuit.Storage battery 5 and diode 6 form low pressure small-power accessory power supply.Direct current voltage sensor 8, AC voltage sensor 9, first AC current sensor 10, second AC current sensor 11 form testing circuit.Controller 12 and drive circuit 13 composition control circuit.A set of stator winding that dual stator-winding induction generator 1 is connected to power inverter 3 is referred to as controlled winding, and dual stator-winding induction generator 1 directly connects loaded another set of stator winding and is referred to as power winding.

Wherein, the anode of diode 6 is connected with the positive pole of storage battery 5, and the negative electrode of diode 6 is connected with the positive direct-current bus of power inverter 3 DC side, and the negative pole of storage battery 5 is connected with negative DC bus.Being arranged on low pressure small-power accessory power supply (24V or 48V) on power inverter DC bus for dual stator-winding induction generator provides initial excitation reactive power power, ensure that dual stator-winding induction generator builds pressure smoothly, when the DC bus-bar voltage of power inverter 3 exceedes the voltage of low pressure small-power accessory power supply, diode 6 oppositely ends, and storage battery 5 and DC bus depart from naturally.

The two ends of low pressure small-power accessory power supply are connected with filter capacitor 7, and filter capacitor 7 is connected by the DC side of DC bus with power inverter 3.The AC of power inverter 3 is three-phase three-wire system, be connected to three filter inductances 2 successively, three exciting capacities 4, the controlled winding of dual stator-winding induction generator 1, such filter inductance 2, exciting capacity 4 form LCL type filter with Electric Machine Control wound stator leakage inductance.The three-phase four-wire system power winding of dual stator-winding induction generator 1 provides variable frequency alternating current power source to load.

Voltage and current transducer is Hall element, and direct current voltage sensor 8 and AC voltage sensor 9 are used for measuring power inverter DC bus-bar voltage and power winding frequency-changing AC voltage, AC current sensor 10 respectively, and 11 are used for measuring winding current.These voltage and current transducers gather the system status signal on main power circuit, for control circuit.Power inverter 3 can adopt IGBT or Intelligent Power Module (IPM) converter.Controller 12 adopts digital signal processor to realize.The signal that controller 12 gathers according to transducer, obtains the drive singal of power inverter 3, then controls the switching tube of power inverter through overdrive circuit 13 after data processing.

Fig. 2 shows the one phase equivalent circuit model of main power circuit, describes LCL type Filter Principle in this variable-frequency alternating current power generation system.LCL type filter 16, be made up of the controlled winding stator leakage inductance in the filter inductance 2 of Fig. 1, exciting capacity 4 and stator double-winding asynchronous 1, topology forms a LCL type filter, use an inductance lesser than common LCL filter, and electric capacity is except filter action, also play effect double-winding AC-DC generator being carried out to excitation.LCL type filter is compared to common single L filter, owing to having the low-frequency filter characteristics on three rank, thus for same harmonic standard and lower switching frequency, can adopt the design of relatively little filter inductance, the volume weight of effective reduction system also reduces loss.

Theoretical according to alternating current machine, the rotor equivalent circuit of double-winding AC-DC generator can represent the conversion of asynchronous machine mechanical output and electrical power with an equivalent simulation resistance, as shown in the stator double-winding motor rotor equivalent circuit 19 of Fig. 2.This equivalent simulation resistance can serve as the passive damping of LCL type filter, plays the effect suppressing LCL type filter own resonance characteristic.

Described variable-frequency alternating current power generation system vector control method, its operation principle is described below:

Pass through coordinate transform, in synchronous rotating frame (dq coordinate system), the DC motor model of equivalence can be obtained, in the model, the magnetic linkage control of motor and direct torque can realize decoupling zero, thus Controlling model can be set up respectively carry out magnetic linkage and direct torque, reach the object controlling motor stabilizing reliability service.

Fig. 3 is the principle of vector control figure of this variable-frequency alternating current power generation system control method, and method comprises the steps:

Step 1, according to AC voltage sensor measured value calculate dual stator-winding induction generator power winding side export alternating voltage effective value u _p, utilize formula (1) to calculate stator flux of motor set-point

${\mathrm{\ψ}}_{\mathrm{\δ}}^{*}=(K_1+K_2\·\frac{1}{p})(u_p^{*}-u_p)+{\mathrm{\ψ}}_0---\left(1\right)$

Wherein: represent the given effective value of power winding output AC voltage, ψ ₀expression system is in stator flux of motor estimated value during quiescent point; K ₁for the proportionality coefficient of proportional and integral controller, K ₂for integral coefficient; P is differential operator, represent Integral Operator;

Step 2, utilizes stator flux observer to set up with the synchronous rotating frame of stator magnetic linkage vector oriented, observation stator magnetic linkage amplitude ψ _δ, and carry out closed loop feedback adjustment, obtain the d shaft current set-point of controlled winding under synchronous coordinate system shown in (2):

$i_{sd}^{*}=(K_3+K_4\·\frac{1}{p})({\mathrm{\ψ}}_{\mathrm{\δ}}^{*}-{\mathrm{\ψ}}_{\mathrm{\δ}})---\left(2\right)$

Wherein: K ₃for the proportionality coefficient of stator magnetic linkage proportional and integral controller, K ₄for the integral coefficient of stator magnetic linkage proportional and integral controller, represent Integral Operator, this closed loop feedback controller forms stator flux regulation device;

Step 3, according to direct current voltage sensor measured value u _cDCwith direct voltage set-point carry out closed loop feedback adjustment, obtain the q shaft current set-point of controlled winding under synchronous coordinate system shown in (3):

$i_{sq}^{*}=(K_5+K_6\·\frac{1}{p})(u_{cDC}^{*}-u_{cDC})$

Wherein: K ₅for the proportionality coefficient of direct-current voltage proportion integral controller, K ₆for the integral coefficient of direct-current voltage proportion integral controller, represent Integral Operator, this closed loop feedback controller forms DC bus-bar voltage controller;

Step 4, utilizes the first AC current sensor Survey control winding current values, obtains the d of controlled winding under synchronous coordinate system, q shaft current i after coordinate transform _sdand i _sq, according to the d of controlled winding under synchronous coordinate system that step 2 and 3 obtain, q shaft current set-point with to the d of controlled winding at synchronous coordinate system, q shaft current carries out closed loop feedback adjustment, and obtain the d of controlled winding under synchronous coordinate system, q shaft voltage is given shown in (4):

$u_{sd}^{*}=(K_7+K_8\·\frac{1}{p})(i_{sd}^{*}-i_{sd}-i_{pd})---\left(4\right)$

$u_{sq}^{*}=(K_7+K_8\·\frac{1}{p})(i_{sq}^{*}-i_{sq})$

Wherein: K ₇for the proportionality coefficient of current closed-loop proportional and integral controller, K ₈for the integral coefficient of current closed-loop proportional and integral controller, i _pdbe that the second AC current sensor is measured and the power winding d shaft current value calculated;

Step 5, according to the d of controlled winding under synchronous coordinate system that step 4 is obtained, q shaft voltage is given with the magnetic linkage angle that stator flux observer is measured adopt Sine Wave Pulse Width Modulation or space vector pulse width modulation, the switching tube of driving power converter, controls amplitude and the rotating speed of stator double-winding asynchronous stator rotating magnetic field, thus the work of control system normal table.

The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (2)

1. a variable-frequency alternating current power generation system, it is characterized in that: comprise by dual stator-winding induction generator (1), power inverter (3), filter inductance (2), exciting capacity (4), the main power circuit that DC filter capacitor (7) is formed, the accessory power supply be made up of storage battery (5) and diode (6), by direct current voltage sensor (8), AC voltage sensor (9), first AC current sensor (10), the testing circuit that second AC current sensor (11) forms, the control circuit be made up of controller (12) and drive circuit (13), wherein:

In described main power circuit, the controlled winding of the AC series filtering inductance (2) of described power inverter (3) connecting stator double-winding AC-DC generator (1) afterwards, described exciting capacity (4) forms LCL type filter with filter inductance (2) and motor stator winding leakage inductance; Described LCL type filter is used for while filtering, utilize exciting capacity to provide idle excitation to dual stator-winding induction generator (1); Described low pressure small-power accessory power supply is used for providing initial excitation for motor; Described testing circuit for detecting DC voltage, AC voltage, the ac-side current in described main power circuit, and transfers to described controller by detecting the detected value obtained; Described controller adopts vector control strategy driving power converter to control.

2. based on a vector control method for variable-frequency alternating current power generation system according to claim 1, it is characterized in that, comprise the steps:

Step 1, according to AC voltage sensor measured value calculate dual stator-winding induction generator power winding side export alternating voltage effective value u _p, utilize formula (1) to calculate stator flux of motor set-point

${\mathrm{\ψ}}_{\mathrm{\δ}}^{*}=(K_1+K_2\·\frac{1}{p})(u_p^{*}-u_p)+{\mathrm{\ψ}}_0---\left(1\right)$

Wherein: represent the given effective value of power winding output AC voltage, ψ ₀expression system is in stator flux of motor estimated value during quiescent point; K ₁for the proportionality coefficient of proportional and integral controller, K ₂for integral coefficient; P is differential operator;

Step 2, utilizes stator flux observer to set up with the synchronous rotating frame of stator magnetic linkage vector oriented, observation stator magnetic linkage amplitude ψ _δ, and carry out closed loop feedback adjustment, obtain the d shaft current set-point of controlled winding under synchronous coordinate system shown in (2):

$i_{sd}^{*}=(K_3+K_4\·\frac{1}{p})({\mathrm{\ψ}}_{\mathrm{\δ}}^{*}-{\mathrm{\ψ}}_{\mathrm{\δ}})---\left(2\right)$

Wherein: K ₃for the proportionality coefficient of stator magnetic linkage proportional and integral controller, K ₄for the integral coefficient of stator magnetic linkage proportional and integral controller;

Step 3, according to direct current voltage sensor measured value u _cDCwith direct voltage set-point carry out closed loop feedback adjustment, obtain the q shaft current set-point of controlled winding under synchronous coordinate system shown in (3):

$i_{sq}^{*}=(K_5+K_6\·\frac{1}{p})(u_{cDC}^{*}-u_{cDC})$

Wherein: K ₅for the proportionality coefficient of direct-current voltage proportion integral controller, K ₆for the integral coefficient of direct-current voltage proportion integral controller;

Step 4, utilizes the first AC current sensor Survey control winding current values, obtains the d of controlled winding under synchronous coordinate system, q shaft current i after coordinate transform _sdand i _sq, according to the d of controlled winding under synchronous coordinate system that step 2 and 3 obtain, q shaft current set-point with to the d of controlled winding at synchronous coordinate system, q shaft current carries out closed loop feedback adjustment, and obtain the d of controlled winding under synchronous coordinate system, q shaft voltage is given shown in (4):

$\begin{array}{c}{u}_{sd}^{*}=(K_7+K_8\·\frac{1}{p})(i_{sd}^{*}-i_{sd}-i_{pd})\\ u_{sq}^{*}=(K_7+K_8\·\frac{1}{p})(i_{sq}^{*}-i_{sq})\end{array}---\left(4\right)$

Wherein: K ₇for the proportionality coefficient of current closed-loop proportional and integral controller, K ₈for the integral coefficient of current closed-loop proportional and integral controller, i _pdbe that the second AC current sensor is measured and the power winding d shaft current value calculated;

Step 5, according to the d of controlled winding under synchronous coordinate system that step 4 is obtained, q shaft voltage is given with the magnetic linkage angle that stator flux observer is measured adopt Sine Wave Pulse Width Modulation or space vector pulse width modulation, the switching tube of driving power converter, controls amplitude and the rotating speed of stator double-winding asynchronous stator rotating magnetic field, thus the work of control system normal table.